Evolution of the Atomic Structure of Ceria-Supported Platinum Nanocatalysts: Formation of Single Layer Platinum Oxide and Pt–O–Ce and Pt–Ce Linkages

This is the authors' abstract. We don't add key points for this paper.

Depending on platinum loading and gas environment vastly different platinum structures in Pt/ceria were observed by Pt L 3 -edge extended X-ray absorption (EXAFS) and X-ray absorption near-edge (XANES) spectroscopies. Calcination of highly loaded platinum (4 wt %) yielded stacked layers of α-PtO 2 . The low platinum-loaded sample (2 wt %), obtained by leaching, consisted of a single layer of α-PtO 2 bonded to the support by Pt–O–Ce linkages. Reduction of the platinum oxide by exposure to a carbon monoxide and hydrogen (PROX) gas mixture led to complete metal reduction at temperatures above 540 K. Under these conditions platinum–cerium bonds with a distance of 2.4 Å were detected and particles of 0.8 and 0.6 nm for the high-loaded and low-loaded Pt/ceria samples, respectively.